JeroenH

Hi,

Iam Jeroen, 18 years old from Holland. For a school project i needed to built a RC car. I could go to the local hobby shop and buy one, but i like to build my own things[8D]. So my journey started.

I also had a few demands for my design.

1 -> No plastic

2 -> Decent transmission, which will peform good under heavy load.

3 -> 4WD

4 -> Four wheel steer

5 -> Low cost

6 -> Strong Chassis

7 -> Overkill electric motor ( I like to overkill things )

So i started so browse on several forums, but like i said before, i could not find any DIY project. But enough blabla, time for pictures!

Stage one : Design in Solid edge

Stage two : Wood prototype

Stage three: Final prototype

Front




Motor:



Specs:

Model: HXT 42-63A
Speed : 600Kv
Max Efficiency : 38A
Max Load : 50A
Weight : 278grams
Thrust : 900~3000gr (12x8 Prop)
Voltage Range : 9~18
No Load Current : 6.3A
Power: 900W
Shaft: 5mm
ESC Required : 70A

In combi with this ESC

http://www.hobbycity.com/hobbycity/s...og/HXT120A.jpg


High rate (10 KHz) switching (PWM)
3 to 6 Li-poly cells with receiver.
Dynamic braking ensures prompt prop folding.
BEC (2.0A) provides power to receiver and servos.
Over temperature protection.
User programmable Features.
Low-voltage protection - Programmable
Cutoff can be programmed for motor stop or reduced power.
Brake Type.
Throttle Range.
Timing Advance.
Safe “power on?arming program.
Low torque “soft start?prevents damage to fragile gearboxes.
Auto shut down in 4sec after signal is lost or radio interference becomes severe.
Microprocessor controlled.
Programmable rotation.

And for 4 wheel steering i bought two 15kg metal gear servo's.


A diff was too expensive for my project, so i used a stiff axle.



Then it was milling time

Bearing block






I was happy with that design, so i moved on with Cad desiging the whole car!

Few weeks later i had this:




As you can see in this picture, i wont be using any gears at all because,

1 Motor has a low Kv, so i dont need a big reduction. I use 1:2 now.

2 This will never ever break. And sand/stone is no problem.

3 You can easily get to the front and back.

Then it was milling time again!

After a few hours





First piece of aluminium



Wheels
radius is 6 centimeters


Motor and accu's with some axels and bearings

http://tweakers.net/ext/f/q68ylkJHX6...D8Qn6/full.jpg









With everything on it..


Wooden prototype almost finshed







Then it was aluminium time





Construction continues



Carbon fiber!





95% finished!



First test video! ( With bad wheel setup etc)

http://www.youtube.com/watch?v=X5F2vYsRAqA

Second test vid! (with pretty good wheel setup)

http://www.youtube.com/watch?v=ClCVSPH3les

Total cost

€320 euro's

And for my first ever designed RC car it runs even better than expected! I only need to change the Battery's. Iam going for A123 cells.

Revotrx3

wow iam in school and my friend korey sitin next to me said it was hott. nice work.

ohgrfreak

That is sic awesome! Can you imagine how many people would love to have access to all the resources to custom build their own car from scratch, insane! Good job [sm=thumbs_up.gif]

kistner

My Feedback: (10)

sweet, I am impressed

hunter306

Very nice work on this.

rschoi_75

That's very impressive.

wookie_racer

My Feedback: (8)

very impressive. i cannot wait to take some more CAD classes now, i hope i end up being able to do something like that lol.

JeroenH

Well CAD drawings are very important If you dont have the resources, you can go with your drawings to a local metalworkshop where they can mill things for you. And you would still get your parts!

@ Wookieracer, what kind of CAD package do you use? I can personally recommend Solid edge. It is not very difficult. I began with Solid edge when i was 14-15 years old. At the beginning it was ofcourse very basic stuff. But once you have a solid base, you can design better/bigger and faster!

There are still some things to improve,

1 -> I had Carbon bearingblocks. But after a few runs, the thread was totally ruined. Now i use some tierips to hold them together. After my exams, i will make them out of aluminium.

2 -> The aluminium axles will be replaced by steel one's. The power that this brushless can deliver is incredible! And it will be even more once i have my A123 cells!

And maby some bigger wheels, so i can get real offroad

dar123

that is sick! i would love to be able to do something like that![X(]

dar123

sorry a bit of a stupid questoin but what is Cad?[&:]

JeroenH

Computer aided design

ohgrfreak

I remember it as Computer Aided Drafting, but of course, I haven't taken a CAD class in over ten years...

dar123

ahh i no what it is now! thanks!

wookie_racer

My Feedback: (8)

i have been traind on autodesk mechanical desktop. i would like to get some experiance on solid works as i hear it is much easier to use. i will have to look into solid edge.

RC_Basher20

My Feedback: (4)

495$ in american $$... how thats cheap for a homemade rc with all alluminum

Longhair

Looks great [sm=thumbs_up.gif]

I probably would have remembered more of my CAD class (R13) if I wasn't dating a dancer [:@]

brushlessboy16

Very nice car, im running the 50-55b in a 1/8th scale buggy. great littlle outrunner

JeroenH

@ Longhair,

Well dating a dancer isn't bad either


Thx all for the good comments

But tell me, when you look at the CAD designs, what would you change? Any comment on my design? If you need specific information, just ask ofcourse

novakmaxx

I want to build a rc for my school.[]